How Mapping The Human Brain Will Help Us Understand Personality And Mental Illness

When asked what makes us human, many people will say that our
large brain is what really sets us apart from the rest of the
animal kingdom. But, even after centuries of searching, we
haven't been able to adequately suss out what about the brain
makes us uniquely human.

It's not the size of our noggin — other animals have bigger
brains, yet don't embody the unique humanness of homo sapiens.
And our brains have the same basic makeup — with the same cells
using the same chemicals to communicate — as the brains of many
other animals. So what is it exactly that makes us different?

In a 2010
TED talk, MIT researcher Sebastian Seung suggested that the
traits that make us human actually come from what he calls our
"connectome" — the connections between different parts of the
brain and even between individual brain cells.

Essentially, he says, "we are our connectome."

For centuries, scientists have been mapping brain regions
associated to different parts of the body and to different
aspects of personality. But now that we know what parts of the
brain control what functions, we need to put humpty dumpty back
together: We need to learn how these functions are incorporated
into a whole.

By understanding the networks that connect different parts of the
brain, researchers are hopeful they will learn how 86 billion
brain cells come together to become one person.

History of connections

The first connectome was created in the 1970s, of the simple
brain of the worm C. elegans. It consisted of 300
individual brain cells and the 7,000 connections between them.

They used a very crude method, which involves slicing thin
sections of brain, staining them with dyes to make the individual
cells visible, and taking individual pictures in sequence to
analyze them.

It took 12 years.

In 2010, the National Institutes of Health set out to decipher
the human connectome using more modern tools: brain scans. So
they implemented a five-year, $40-million initiative that aims to
map the brain’s communication network — the brain connections
that make up the brain. It's called the Human Connectome
Project.

The group is in their third year of investigating these brain
connections. The first two years were spent investigating and
refining the tools they would use to do this. The next three will
be spent scanning brains, analyzing data and analyzing the
genetics of the participants.

Latest research

Using a scan called the resting state functional Magnetic
Resonance Imager (fMRI), and several other tests, the researchers
involved in the Human Connectome Project have started mapping
these connections.

Different from most other fMRI scans, which show how blood flow
changes indicating which parts of the brain are active while
performing a task, the resting state test studies the brain while
you aren't doing or thinking about anything in particular.
Researchers study the brain in this resting state to see how the
brain works during a task or certain thought process.

The team will use the optimized methods to scan the brains of
1,200 individuals to map their connectomes. As the data from
these people comes out, it will be published on the
human connectome project website. They've already released
data from the first 12 subjects, and 80 more sets of information
will be released in February 2013.

The participants picked will be specially selected. For example,
subjects might include sets of twins and their non-twin siblings.
This will help the researchers get a better idea of how much
these brain patterns are determined by genetics. To this end,
they will also be collecting genetic data on all the
participants, so they can map what genes create these
differences.

A second human connectome team is developing new brain scanning
technologies that do an even better job of analyzing the
connections in the brain. There's also a group in Europe working
on a project called CONNECT, and Seung has developed new ways to
analyze the brain connectome on a cellular level.

Initial data from the the second human connectome team shows that
these brain connections run in a pretty organized fashion,
similar to the way cloth is weaved. Bundles of fibers run
perpendicular to each other — some going from front to back while
other connections go from the inside out.

Not everyone is sure that this data will be useful. In an
October
2012 article about the Human Connectome Project in the journal
Science, Greg Miller writes: "Critics contend that
deciphering brain function from a circuit diagram — no matter how
detailed — is like trying to figure out what a computer does by
studying its wiring diagram. In both cases, the circuitry may say
something about what the machine is capable of, but it's the
precise pattern of electricity coursing through it at a given
time that determines what it's actually doing."

Mental health applications

Researchers working on connectome projects disagree. They believe
that studying the brain connections will not only help us get a
better grasp on how our brain works to make us who we are, but it
will also reveal what goes wrong in mental health disorders like
schizophrenia and depression. These diseases could be caused by
changes in the brain's connections, so getting a better
understanding of how the brain works together is vitally
important.

"There is huge potential for miswiring," Seung said in the
TED talk. "In truth we can't see the brain's
wiring clearly enough to tell if this is really true. The
technology to see connectomes will allow us to finally read
miswiring of the brain, to see mental illnesses in the
connectome."

As data from the Human Connectome Project continues to dribble
out over the next few years, researchers will have a treasure
trove of information to muddle over as they contemplate how these
connections make us who we are, or who we aren't.